1. Prof., Civ. Engrg. Dept., Clemson Univ., Clemson, SC 29634-0911. E-mail: hsein@clemson.edu
2. Transp. Engr., California Dept. of Transp., 5900 Folsom Blvd., Sacramento, CA 95819.
3. Res. Asst., Civ. Engrg. Dept., Clemson Univ., Clemson, SC 29634-0911.